Hosting and cloud
AS7203 LEASEWEB-USA-SFOASN lookup: IP ranges, prefixes and network type
AS7203 is the autonomous system number (ASN) announced by LEASEWEB-USA-SFO. It announces 128 prefixes, 184,320 IPv4 addresses in total. Every address inside those ranges is routed by this operator, which is what makes the number the shortest answer to who runs a given address.
AS7203 at a glance
| Organisation | LEASEWEB-USA-SFO |
|---|---|
| Autonomous system | AS7203 |
| Network type | Hosting and cloud |
| IPv4 prefixes | 104 |
| IPv6 prefixes | 24 |
| IPv4 addresses | 184,320Summed across every announced prefix. IPv6 is not counted; the numbers are meaningless at that scale. |
| In known VPN ranges | 0 of 104 prefixes |
| In known datacenter ranges | 104 of 104 prefixes |
The last two rows are a second opinion, counted against the X4BNet VPN and datacenter range lists rather than read off the operator name. A network with most of its prefixes in the VPN list is carrying anonymised traffic whatever it calls itself.
Sample prefixes
The largest ranges LEASEWEB-USA-SFO announces, biggest first. These are a sample and not the full routing table: 128 prefixes do not fit on a page, and the ones worth showing are the ones most traffic comes from.
| Prefix | Family | Addresses |
|---|---|---|
| 23.105.96.0/19 | IPv4 | 8,192 |
| 23.108.160.0/19 | IPv4 | 8,192 |
| 23.81.96.0/20 | IPv4 | 4,096 |
| 23.82.16.0/20 | IPv4 | 4,096 |
| 23.105.16.0/20 | IPv4 | 4,096 |
| 23.106.160.0/20 | IPv4 | 4,096 |
| 147.255.48.0/20 | IPv4 | 4,096 |
| 147.255.176.0/20 | IPv4 | 4,096 |
| 172.255.112.0/20 | IPv4 | 4,096 |
| 172.255.208.0/20 | IPv4 | 4,096 |
| 209.58.128.0/20 | IPv4 | 4,096 |
| 23.19.88.0/21 | IPv4 | 2,048 |
Look up an address on AS7203
The field is prefilled with 23.105.96.1, the first address of the largest range above. Change it for one from your own logs and you get the network, the operator and the verdict for that specific address.
What AS7203 means for detection
Addresses on LEASEWEB-USA-SFO are infrastructure: servers, containers and managed services, not people at home. Our engine classifies them datacenter or hosting and never as VPN, because renting a machine is not anonymising traffic. That distinction matters for what you do next. A signup from here is worth a second look because automation lives on networks like this one, but blocking the range outright also blocks every monitoring service, payment webhook and corporate proxy that runs on it.
The verdict for a single address is never settled by the ASN alone. It is the starting point, and IP Detection adds range membership, behaviour and history on top of it before it answers.
Related networks
The same page as JSON
No key and no signup. This is the endpoint this page is rendered from, so anything you read here you can script against.
curl https://ipscanner.io/v1/asn/directory/AS7203
IPScanner. AS7203 LEASEWEB-USA-SFO, ASN directory. https://ipscanner.io/nl/asn/as7203. Derived from MaxMind GeoLite2.